Just in time for your Superbowl party....A study conducted at Clemson University by a food microbiologist and his undergraduate students tested the amount of bacteria transferred by double dipping.
"On average, the students found that three to six double dips transferred about 10,000 bacteria from the eater’s mouth to the remaining dip." Here's the full article from the New York Times.
I'm not a germophobe at all, but I've never been a double dipper. Well, that's not exactly true...if I'm eating a carrot stick or something, I'll dip, bite, then redip, but from the unbitten end, not with the part that my mouth has touched. Um, in case anyone was wondering.